1. Field of the Invention
The present invention relates to a preamble change method and system for a moving network system and, in particular, to a preamble change method for minimizing data loss when preamble collision occurs between relay node operating in non-transparent mode and system therefor.
2. Description of the Related Art
In a broadband radio access system, a direct link is established between a base station and a mobile station such that it is possible to establish the radio communication link between the mobile and base station in high reliability. However, the fixed location of the base station decreases the flexibility of the radio network configuration and, as a consequence, makes difficult to provide services efficiently in the radio environment in which the traffic distribution and call request amount are varying abruptly. In order to overcome this problem, a relay system for delivering data over multiple hops with adjacent relay stations is proposed in the broadband radio access system. The multi-hop relay system is advantageous to reconfigure the network quickly according to the ambient environment of the system such that it is possible to manage the entire radio network more efficiently. Accordingly, the self-adaptive radio communication network required in the next generation mobile communication system can be actually implemented with the multi-hop relay broadband radio access communication system model.
In the multi-hop relay broadband radio access communication system, the moving network means of network architecture simplifying the handover process as well as providing high quality service to each mobile station with the installment of relays along the paths on which a plurality of mobile stations are moving such as bus and train. In the moving network environment, since the relay provides the mobile stations with the service directly, the relay operates in non-transparent mode to transfer the preamble and MAP. Since the relay transmits the preamble directly, the movement of the relay close to the base station or a fixed or mobile relay using the same preamble causes collision of preambles.